WASHINGTON (MEDIA GENERAL) — National political conventions are a rare opportunity for politicians to greet a national audience and make a big impression.

Sometimes those moments are career-makers. For others, they’re career-breakers.

If done right, rising stars can carve out a spot for themselves in parties’ upper echelon, leapfrogging other aspirants in one short speech.

If flubbed, the bungled impression can take years to shake.

Here are 10 of the best and worst convention moments of the past 40 years.

1. Sarah Palin: Hockey mom

Alaska Gov. Sarah Palin was a virtual unknown when Republican nominee John McCain tapped her as his running mate in 2008.

The nation got its first good look at the VP nominee during her keynote address at the RNC convention in St. Paul, Minnesota — and she nailed it.

Palin’s folksy, plain-spoken style was on full display in the speech. So much so that the audience never knew her TelePrompTer was badly malfunctioning.

Unflapped, Palin threw in a joke, “You know they say the difference between a hockey mom and a pitbull? Lipstick.”

It brought down the house and immediately ingratiated Palin to millions of Americans.

2. Barack Obama: Red states, blue states

Illinois State Senator Barack Obama was running to become his state’s next U.S. senator in 2004.

The 42-year-old’s big shot at political stardom came when he was given a keynote slot in primetime.

Obama’s remarks were a seamless amalgam of sermon and stump speech, showcasing his soaring oratory focused on America’s bright future.

“The pundits, the pundits like to slice and dice our country into red states and blue states,” said Obama. “Red states for Republicans, blue States for Democrats. But I’ve got news for them, too. We worship an awesome God in the blue states, and we don’t like federal agents poking around our libraries in the red states.”

Following that breakthrough July evening, Obama was eyed as a future leader among top Dems.

3. George H.W. Bush: Read my lips

President George H.W. Bush became a one-term president, thanks in large part to a speech he delivered at the 1988 RNC convention in New Orleans.

As the GOP’s nominee, then-Vice President Bush made a public pledge that would live in infamy: “Read my lips, no new taxes.”

That pledge earned Bush huge applause at the convention, and a one-way ticket back to Texas, post-dated for 1992.

Bush hiked taxes in 1990 and lived to regret his “no new taxes” line, which became a rallying cry for fiscal conservatives and fodder for comedians like SNL’s Dana Carvey who helped paint Bush as limp and ineffective.

4. Bill Clinton: The never-ending speech

Arkansas Gov. Bill Clinton considered a run for the presidency in 1988, but decided to bide his time and wait until the next cycle.

He did, however, get a speaking slot to introduce Michael Dukakis at the ‘88 convention and wound up being roundly mocked for his interminable speech.

After 32 minutes of droning, Clinton uttered the words “In closing” and the restless audience erupted in applause.

In a convention hall filled with party loyalists, you know you’re in trouble when their highest hope is that you’ll zip it.

Clinton quickly recovered when he went on The Tonight Show with Johnny Carson.

Carson greeted Clinton, asked how he was doing and then pulled out an hourglass to time his answer. Clinton howled, along with the audience, and all was forgiven.

5. Ann Richards: Poor George

Not many people could tell you the name of Texas’ state treasurer before the 1988 Democratic National Convention.

Once Ann Richards delivered her stem-winder, everything changed.

Richards, with her sky-high beehive and deep southern drawl, skewered fellow Texan and GOP presidential nominee George H.W. Bush as an out of touch blue blood.

“Poor George,” Richards irreverently teased, “he was born with a silver foot in his mouth.”

Richards won her gubernatorial bid two years later, making her the first female governor of the Lone Star State elected in her own right.

6. Hillary Clinton: Obama supporter

But when the time came to unite the party, Clinton, ever the dutiful party soldier, stepped onto the DNC stage and heaped her full support on the victor.

Clinton declared, “Barack Obama is my candidate. And he must be our president.”

It wasn’t an easy moment for Clinton, but it set her up for two things: becoming Obama’s secretary of state and demanding full support from fellow Dems eight years later during her own nomination fight.

Thanks to her 2008 actions, Clinton was also viewed as loyal to the country’s first black president and cemented her positive standing among minority voters, which became a reliable and crucial voting bloc in her 2016 triumph over Sen. Bernie Sanders.

7. Jimmy Carter: Balloon drop

President Jimmy Carter’s 1980 convention in New York City passed rather unremarkably.

In fact, it’s something that didn’t happen which grabbed the most news.

At the end of Carter’s acceptance speech for the Democratic nomination, the planned balloon drop turned out to be a stink bomb.

The band played. The candidate cheesed. Cameras zoomed in on the ceiling.

What started as a hip song of youthful frivolity was soured for young people the world over by the nationally televised gyrations of middle-aged delegates draped in all manner of political paraphernalia.

9. Al Gore: The kiss

Al and Tipper Gore are no longer married, but they were once a seemingly blissful couple that notoriously shared a big, wet smooch in front of a startled nation.

In 2000, then-Vice President Gore had accepted the Democratic nomination and greeted his wife on stage to the whoops of adoring delegates.

Whether out of exuberance or overcompensation, the nominee, who’d been endlessly lambasted as boring and starchy, laid a mammoth of a kiss on Tipper (56:00 mark).

Their lip-lock seemed to last an eternity — and Gore certainly never heard the end of it throughout the election cycle.